A person can descend quickly from a height by using a rope and a rapid descent device that provides a braking force to counteract the person's weight on the rope. Such devices may be used, for example, by civilians evacuating a building via an exterior of the building, such as when all other exits are blocked or no longer available. Such devices may also be used, for example, by firefighters and/or rescue workers descending rapidly from a burning building, and/or by any person working at a height.
Existing rapid descent devices often include simple drive wheels capable of being driven at a single speed equivalent to the rope speed. The braking force imparted by such rapid descent devices is thus the same for a very heavy load and a very light load, for any given rope speed. Such devices also typically do not permit rope slippage during shock loading or manual rope advancement.